Swift3: Add button with code - ios

Question

Im reading Apples swift (iOS) documentation but its written for Swift 2 and i use Swift 3. I want to add a button programmatically but its seems there is a change and I can't find how to fix it.
Here is the Code for the Swift 2 example:
import UIKit
class RatingControl: UIView {
// MARK: Initialization
required init?(coder aDecoder: NSCoder) {
super.init(coder: aDecoder)
// Buttons
let button = UIButton(frame: CGRect(x: 0, y: 0, width: 44, height: 44))
button.backgroundColor = UIColor.red()
button.addTarget(self, action: #selector(RatingControl.ratingButtonTapped(_:)), forControlEvents: .TouchDown)
addSubview(button)
}
override func intrinsicContentSize() -> CGSize {
return CGSize(width: 240, height: 44)
}
// MARK: Button Action
func ratingButtonTapped(button: UIButton){
print("Button pressed")
}
}
The only change i made after the 'fix-it' showed the error is this in the selector:
button.addTarget(self, action: #selector(RatingControl.ratingButtonTapped(button:)), for: .touchDown)
This should have printed "Button pressed" but it doesn't. Any help?

Answer 1

My code:
button.backgroundColor = UIColor.red
button.addTarget(self, action: #selector(RatingControl.ratingButtonTapped(_:)), for: .touchDown)
override var intrinsicContentSize : CGSize {
//override func intrinsicContentSize() -> CGSize {
//...
return CGSize(width: 240, height: 44)
}
// MARK: Button Action
func ratingButtonTapped(_ button: UIButton) {
print("Button pressed 👍")
}

Answer 2

Try something like this. I haven't tested but it should work:
let button = UIButton(frame: CGRect(x: 0, y: 0, width: 44, height: 44))
button.backgroundColor = UIColor.red
button.addTarget(self, action: #selector(ratingButtonTapped), for: .touchUpInside)
addSubview(button)
func ratingButtonTapped() {
print("Button pressed")
}

Answer 3

Found the solution. For some reason the:
func ratingButtonTapped(button: UIButton)
needs an "_" before button. So it should be :
func ratingButtonTapped(_ button: UIButton)
And the other part of the code must be :
button.addTarget(self, action: #selector(RatingControl.ratingButtonTapped(_:)), for: .touchDown)
Thanks for helping :) Your method may be correct also but thats the one Apple wants it.